When the Impossible Man first appeared,[1] he was different from previous guest stars in that he was not a villain. The team first meet him at the Flamingo restaurant when they are summoned there to investigate a disturbance. Written by Lee to be a prankster and hedonist, the Impossible Man claimed to belong to the alien race of Poppupians from planet Poppup in the "Tenth Galaxy", who all share a collective consciousness and the ability to shapeshift, as their planet is so dangerous they have the ability to evolve very quickly. Seeking amusement, the character visits Earth for a vacation by turning himself into a spaceship, talking of a Poppup Tourist Bureau. After finding the superhero team the Fantastic Four and realizing nobody else on Earth has his power (therefore concluding he is the most powerful being on Earth), he constantly harasses them until they decide to ignore him and tell other people to do the same, forcing the Impossible Man to leave as he finds Earth so boring, and saying Earth will never get their tourist business. He gets his name after the Thing claims he is "impossible".[2]

The character does not appear again until 1976. Acting as a deus ex machina in a storyline involving the cosmic entity and world-devourer Galactus, the Impossible Man convinces the character to consume his homeworld Poppup instead of Earth.[3] The Impossible Man then makes a humorous appearance at the offices of Marvel Comics, where he causes havoc until Stan Lee promises to give him his own title.[4]

He offers peripheral assistance to the Fantastic Four when they are trapped in the Negative Zone by the Frightful Four, a team of their enemies.[5] The Impossible Man impersonates Jimmy Carter, on the day when he is to be inaugurated as President of the United States, and briefly takes his place to foil an attempt to enslave him during an adventure with the Thing and the cyborg Deathlok.[6] He later saves the Invisible Woman from a fall[7] and becomes fascinated with Earth movies.[8] When returning to the Baxter Building, headquarters of the Fantastic Four, the Impossible Man is surprised and defeated by the villain Klaw, who, in an alliance with the Molecule Man, attempts to kill the Fantastic Four.[9] During the course of the storyline, the character recovers and, courtesy of his abilities, mimics and defeats Klaw in turn[10] and assists the Fantastic Four in stopping the Molecule Man.[11] The character continued his trend of general disruption during a visit to Hollywood with the Invisible Girl.[12]

After helping the Thing defeat several villains at a party, the Impossible Man observes the Thing with his partner Alicia Masters and becomes lonely. The character then decides to reproduce - here an asexual process - by splitting in two. This creates fellow Poppupian the Impossible Woman.[13] The pair later attempt to recreate their race and create the Impossible Kids, with the entire "family" visiting the Thing.[14] When the Impossible Woman is missing, the character hires private investigatorJessica Drew to locate her,[15] and has an encounter with the mutant X-Men after stealing artifacts from Earth to settle a supposed family dispute with the other members of his race.[16]

The Impossible Man finds and teases the cosmic being the Silver Surfer on two occasions, pleading for him to develop a sense of humor before battling the titan Thanos.[20] The character returns to Earth and causes more mischief,[21] encounters the hero Daredevil while looking for a lost child,[22] starts a bar fight,[23] watches the EternalMakkari win a galactic marathon,[24] and invited various otherwise un-contacted heroes and supervillains to the wedding of Rick Jones.[25]

After a brief encounter with the young superhero team the New Warriors,[26] the character enlists the aid of mutant team X-Force to instill some pride in his children,[27] and enters into a wager with the alternate universe impMister Mxyzptlk.[28]

The Impossible Man and the Poppupians make a cameo appearance in Noh-Varr's origin story.[29]

The Impossible Man returns to Earth disguised as the Silver Surfer, and after teasing the hero Spider-Man warns of an alien invasion. The Impossible Man's race are also revealed to have survived, with their consciousness stored inside the character. With the aid of the Fantastic Four, the aliens and the newly-reborn Poppupians are transported off world, merging into one race on Spider-Man's suggestion.[30]

Later during the Chaos War, the Impossible Man confronts Mikaboshi, trying to humor and reason with him while shapeshifting in various forms to divert him, but the Chaos King tires of him and brutally dispatches him. Impossible Man's last words were "I thought we were just playing around..."[31]

Impossible Man returns to Earth where he witnesses a battle between Hulk, Red Hulk, and Xemnu. Impossible Man uses his magic to combine Hulk and Red Hulk into the Compound Hulk. Impossible Man watches as the Compound Hulk fights Xemnu's minion Kluh (a smart version of the Gray Hulk).[32]

Impossible Man is later shown to have a son named Adolf Impossible who has many of his father's fantastic powers and has a much more introverted personality. This caused Impossible Man to label Adolf as "entirely too possible" and plead with the Future Foundation to accept him and allow him to grow as a person.[33]

The Impossible Man's alien physiology gives the character the ability to take on virtually any form via molecular rearrangement. Almost every appearance has featured the Impossible Man mimicking another Marvel character's appearance and their abilities, such as Thor,[9]Klaw,[34] and Wolverine.[35] He also has the ability to teleport across vast interstellar distances and even dimensions, an effect commonly accompanied by a "Pop!" sound effect.

The Impossible Man once battled the New Mutants' Warlock to determine whose shape-shifting ability was superior, a contest Warlock won when he showed he was able to change his colors to match those of the forms he mimics, while the Impossible Man could not.[36] This was not the case when he first appeared, however; for instance, when impersonating the Invisible Girl in order to trick Galactus into consuming Poppup, he was fully capable of changing color to make his disguise perfect.[3]

The Impossible Man has an encyclopedic knowledge of Earth's popular culture.

Impossible Man appears in the spoof comic "Wha...Huh? #1"(2005) in the segment titled "What If Identity Crisis Happened in the Marvel Universe". He appears as a villain that few of the heroes remember.[volume & issue needed]

The Impossible Man appears in Excalibur (Vol 1) #14, during the Cross-Time Caper. He has populated an analogue of the Earth with multiple twisted versions of the superheroes of the Marvel Universe (such as Daredevil, the 'Man without Common Sense'). This version of the Earth is destroyed by Galactus, who deems it "Too silly to be allowed to exist", and deems the Impossible Man as "In your own way... as great a threat as the Phoenix". Once Galactus leaves, the Impossible Man repopulates the planet effortlessly, allowing the mayhem to begin again. His powers in this reality generate a 'Pip' rather than a 'Pop'.[volume & issue needed]

Jess Harnell reprises his role as Impossible Man in The Super Hero Squad Show. In the episode "Tremble at the Might of...MODOK!", Impossible Man appears at the Supervillain Big Heads Convention held by MODOK. In the episode "Missing: Impossible!", Impossible Man appears on the Helicarrier where he causes mischief for the Super Hero Squad like replacing the hammers with chickens, having the coffee beans with radioactive jumping beans, and taking control of the rebuilt Helicarrier. Upon exiting the ventilation, Impossible Man introduces himself and tells about his origin including his history with the Fantastic Four. Repaying Ms. Marvel's visit to his planet, Impossible Man wants to live with her for a while. Impossible Man states that his wife kicked him out and wasn't listening what she was saying. Impossible Man states that he'll be a good house guest. Impossible Man helps to fix one of the doors on the Helicarrier, attempting to fix the electronics, and having Hulk help him to repaint the Helicarrier. The Super Hero Squad plan to find a way to get Impossible Man and his wife back together where they plan to find a way to impress her without the involvement of pranks. With the suggestion of Thor, the Super Hero Squad plan to have Impossible Man fight the Dark Surfer. Impossible Man finds Dark Surfer and challenges him to a duel. Impossible Man's fight with the Dark Surfer shakes the fabric of reality where they end up fighting in Asgard with Skrulls in the background, freeing Doctor Doom, Abomination, and MODOK from their photo prison in Thanos' wallet, and putting the Silver Surfer in the Positive Zone. When Impossible Man creates a black hole to suck the Dark Surfer in, the black hole ends up growing. Impossible Man works to find a way to plug up the black hole. After the Super Hero Squad had regained control of the Helicarrier, they caught up with Impossible Man where they help him fix the black hole. Impossible Man manages to use his rear end to plug up the black hole until a plug that Mister Fantastic makes is placed. Impossible Man's wife arrives where the Super Hero Squad tells her of his heroics and that she could get back together with Impossible Man. Impossible Man and his wife then leave to start a family by adopting. Impossible Man is then seen at the Mayor of Super Hero City's office finishing the Mayor of Super Hero City's story.

Impossible Man appears in the Avengers Assemble episode "Avengers: Impossible", voiced by Tom Kenny. He arrives on Earth where he witnesses Falcon during the Avengers' fight with the Wrecking Crew. Impossible Man then frees the Wrecking Crew for the second take on his show on Falcon so that he can have Falcon defeat them. Iron Man states that S.H.I.E.L.D.'s rating on Impossible Man is at a 10. Hulk breaks the cage that the Avengers were trapped in while Falcon takes out the Wrecking Crew. The Avengers trap Impossible Man and end up taking him back to Avengers Tower. Impossible Man teleports away and shows a trailer which ends up summoning Attuma. During the Avengers' fight with Attuma, Impossible Man mentions to Falcon that he brought him in so that Falcon can defeat him. Impossible Man then spices up his show on Falcon by bring in Ulik, the Midgard Serpent, and Wendigo until Falcon causes Impossible Man to scrub the scene and make the villains disappear. Impossible Man admitted that he was making a documentary on the Chitauri, who then arrive on Earth. Impossible Man films the scene where Falcon and the rest of the Avengers fight the Chitauri. Falcon then convinces Impossible Man to send the Chitauri far far away from Earth by deputizing him in one scene as an Avenger. Impossible Man shapeshifts into an intergalactic missile to send the Chitauri far far away from Earth. Impossible Man returns to pick up his camera and plans to return where he picks up his camera to enter his movie into the film festival. Impossible Man also plans to see Falcon again when he makes out his script for the sequel.

Impossible Man appears in Hulk and the Agents of S.M.A.S.H.,[37] in the episode "Mission Impossible Man", voiced again by Tom Kenny. He arrives at the base of Agents of S.M.A.S.H. posing as Fin Fang Foom where he fought them until Hulk saw through his ploy. Hulk even mentioned that the Avengers have a record on Impossible Man. Impossible Man states that wants to join the Hulks where he transforms into a Hulk version of himself. Impossible Man even used his powers to combine Hulk and Red Hulk into the Two-Headed Compound Hulk. When Sauron attacks a seaside amusement park with an army of prehistoric sea creatures, Impossible Man joins the Agents of S.M.A.S.H. into fighting Sauron. When Impossible Man manages to trap Sauron, his powers are drained by Sauron who uses them to fight the Agents of S.M.A.S.H. even when he summons the real Fin Fang Foom. After Impossible Man regained his powers and Fin Fang Foom knocked Sauron far out into the ocean, Impossible Man borrows a device from Henry Pym's laboratory which he uses to grow the Two-Headed Compound Hulk to large size where he tosses Fin Fang Foom out to sea. Impossible Man then leaves to get his footage uploaded. Impossible Man then returns to split the Two-Headed Compound Hulk back into Hulk and Red Hulk. When Impossible Man asks if he can join the show as their next door neighbor, Hulk and Red Hulk end up punching Impossible Man.